Cartridge for automatic guns



Oct- 30, 1951 s. KELLER ETAL 2,573,451

CARTRIDGE FOR AUTOMATIC GUNS Filed April 26, 1947 Fig.7

i W ,2 i; 111 \LI )1] ATTORNEYS projectile.

Patented Oct. 30, 1 951 Zurich, Switzerland; assignors to Machine Tool Works. Oerlikon Administration Company, Zu-

rich=erlikon,

Switzerland Switzerland,

a company of A'pplicatioiiApi-il 26, 1947,Se1 ialNo.-744,150

' In Switzerland November- 13, .1942

Section 1, Public Law 690', AugustSQIEHB Patent expires November 13,1962

1 Claim.

In cartridges for automatic guns it is the usual practice to draw the cartridge case on the projectile up to the guiding ring provided on the projectile. In most cases the cartridge case is fastened on the projectile by rolling the neck of the cartridge case into a groove cut on the projectile, so as to prevent the cartridge case from being stripped 01f rearward, whilst its forward movement is limited by the stop on the guiding ring of the projectile. The use in inertia-locked automatic fire-arms of cartridges of such design has now shown that the cartridge very frequently falls in front of the extractor claw, thus preventing ignition.

Thi occurrence is a consequence of the fact that when being introduced into the cartridge chamber by the breechblock on its forward stroke the cartridge first receives a blow which imparts to it a velocity exceeding the velocity of the breechblock on its forward travel. Thus, when leaving the magazine, the cartridge moving in advance of the breechblock falls in front of, and not into, the extractor claw.

The subject of the present invention is a special design of the cartridge, intended to prevent the cartridge from being accelerated overmuch by the breechblock in it forward travel, and consequently from falling in front of the extractor claw. According to the present invention this object is secured by designing the cartdige in such a manner that it damps the blow struck on it by the breechblock. For this purpose, the cartridge case may be fastened on the projectile shoulder at a certain interval from the guide ring of the The fastening may be secured by the cartridge case being made conically crimped in front and also made to fit a corresponding tapering shoulder of the projectile. The cartridge case may also be fastened in a groove of the projectile by means of a fold. The cartridge case may further consist of several parts, these being designed so as to be slidable one over the other. The case bottom may be inserted into the case by means of a fine thread which under the blow of the breechblock undergoes a slight deformation, thus exercising a damping effect. Finally, the case bottom may be provided with deformable elevations.

It has been found that a cartridge designed according to the invention does not fall any longer in front of the extractor claw. This is due to the fact that the blow struck by the breechblock travelling forward on the cartridge to be introduced into the cartridge chamber does no longer cause the cartridge to travel in advance of the breechblock, the blow in this case merely forcing the cartridge case on to the projectile, or deforming the case itself, or the case bottom, at the spots intended for this purpose. In any case, care must be taken that the power required to bring about the deformation of the case in any one of the contemplated forms should be less than the 'moment of inertia of the projectile a it results from the projectile mass and the acceleration imparted to it by the breechblock. Practice has shown that this condition is capable of being fulfilled whilst retaining the required resistance to the extraction of the projectile out of the case. Experience has further shown that it is possible to secure that any blows or shocks that may occur during transport should not bring about the deformation or displacement of cartridge case and projectile in relation to one another.

In Figs. 1 to 6 of the attached drawing are shown a few constructional examples of realisation of the subject of the present invention.

In the example according to Figs. 1 and 2 the cartridge case I is conically crimped at its foremost end 2. With this tapered crimp 2 the cartridge lies on a corresponding cut (recess) 3 of the projectile. The projectile itself is provided with a guide ring 4 located at a small distance 5 from the tapered recess 3. Fig. 1 shows the position of the projectile in the cartridge case during transport. Fig. 2, on the other hand, shows the position of the cartridge case I in relation to projectile 6, after the cartridge has been introduced into the cartridge chamber by the breechblock on its forward travel. Under the effect of the blow struck in the process of introduction the cartridge case has been forced on to the projectile 6 until, with its foremost end 2, it gets into contact with the guide ring 4 of the projectile 6.

In the example shown in Figs. 3 and 4 the case I is designed in two parts. Parts I and 8 of the case I are shoved on to one another and fastened together by means of the wavy shape of the parts overlapping each other. Parts 1 and 8, however, are not in contact at the shoulders 53 and [0. It is only under the effect of the blow struck,on the case in the process of introducing the cartridge into the cartridge chamber that the parts 7 and 8 are shoved on to each other until they are in contact at the stops 9 and I6, and take up the position represented in Fig. 4.

In the example of Fig. 5 the bottom H is inserted in the case I by means of thread I2. The fine thread I2 is deformed at the moment of impact of the breech on the case bottom H, this latter being forced into the case I.-

Finally, Fig. 6 shows a constructional example in which the damping of the blow struck on the cartridge by the breechblock takes place by means of slightly deformable elevations l3 provided on the case bottom.

We claim:

In combination with a projectile having a rear end with a recess having a forward portion of uniform depth and a tapered rear portion, and a guide ring located contiguously 'to the forward portion of said recess, a cartridge case having a foremost crimped portion enclosing said rear end of the projectile and located within said recess and terminating at a distance from said guide ring during transport, said cartridge, casefmoving in relation to said projectile and the foremost 5 portion thereof contacting said guidering as ,a

result of a blow upon said cartridge case. 1

SIEGFRIED KELLER; ERNST KELLER. 3 1

. Number REFERENCES CITED The following references are of record'iin the file of this patent: 7 I v UNITED STATES PATENTS Name Date 483,656 Marga Oct. 4, 1892 2,263,941 Albree Nov. 25, 1941 m 2,388,094 Snell Oct. 30, 1945 I FOREIGN PATENTS Number Country Date 10,039 Great Britain of 1912 721,585 France Dec. 22, 1931 

